Block-signal system.



PATENTED 00123, 1906. L. A. HAWKINS. BLOCK SIGNAL SYSTEM.

APPLICATION PILED APB. 7, 1906. r

4 SHEETBSHBET 1.

1 #wentor Laurence Af/aw/r/n's Witnesses 4 SHEETS-SHEET 2.

PATENTED OCT. 23, 1906.

#Wehton: Laurence Af/dwlr/hs By,%r/ 5 AM L. A. HAWKINS. BLOCK SIGNAL SYSTEM. APPLICATION IIILED APB.7,19($6.

W/it/vesses;

Ans-' PATENTED 00-1". 23, 11906.

L. A. HAWKINS. BLOCK SIGNAL SYSTEM.

APPLICATION FILED APB-7,1906

4 SHEETS-SHEET 4.

- //7z/e/7t0/*.- Laurence W/tnesses:

AHaW/r/ns 9 f I Atty.

tems for electrically-operatedroads employing the rails as the return-conductor for the power-current. II

'tice to form connections between the adjacent blocks of thesame track adated to af-,

v No. 834,129.

UNITED STATES LAURENCE A. HAWKINS, I

GENERAL ELECTRIC ooMPA NY,

OF SUHENEGTADY,

PATENT OFFICE,

A CORPORATION OF EW YORK.

BLOCK-SIGNALSYSTEMQ 1 Application filed April. 7,

I Specification of Letters'Patent.

Patented Oct 23,1906. 1906 s mmations.

- flo all whom it may concern: v I

Be'it known that L'LAIURENOE A. HAW-- United States, residing at Schenectady,-county of Schenectady, State KINS, a citizen of the of New York, have invented certain new and useful Improvements in Block-Signal Systems, of which the following'is .a specification.

My invention relates to block-signal: sys- In such roads it is the praciord a path for ranged'that the from-one block to another;

power-current, ut so arofforming this connection are well known in the art. It also sometimes becomes desirable to cross-connect arallel. tracks, so that if the rail-circuit of a lock of one track has an unduly hi h resistance, due to defective bonding, it wi 1 not in the system, since another track is connected in parallel with it nection betweenthe tracks introduces cer- I taindifhcu-lties, since a block-signal system source of danger;

as ordinarily arranged will not detect, a broken rail if the tracks arecross-connected.

I This is obvious from the fact that one .or both rails of each block are connected in parallel with another track, so that a break ma "oc- .curin the rail without opening the si'gna -circuit. Consequently a I whole rail might be removed and the signal for that-block nevertheless give a clear indication.

The object of my invention is to avoid this and my invention in its broadest aspect consists of providing auto sists in insertingaswitch in the cross connec.

tion from an end of'a block to the other track the preceding block for breaking the the prece ing bloc v5O matic mea ns controlling the cross connections and arranged to break the tions at the proper time.

More speclfically stated, my invention conand providing means, controlled by a tra n in cross connection.

train is ap roachini broken in that block the signal.

My invention further comprises an arrangement of the automatic controlling means it will. be indicated by s1gnal-current will not ass- Several met ods'-.

produce a drop of voltage This cross cons cross connec In other words, whenever'a a block its presence in serves to isolate the' lock it is approaching, so thatif a rail is suchthat the cross connections are never broken except when f necessary for. safety. For this purpose I control theswitch 'in the cross-connection not only by a train in the I so that if the signal is already at danger 00111160131011 is not 0 (mod, and just as soon as the signal goes to tering the. block the switch is theblock to which the switch belongs,

block is at clear ceding block. y' invention will best be understood by reference to the accompanying drawings, in

and a train is in the pre- Fi ure 1 shows diagrammaticallan electrical I signal system arranged .in'accordance withmy invention, and Fig tions.

portions of three locks m one track, and A,

other track.

, lower-current 'i. e. 'ey-wlres.

ftrac -circuits fthe alternating-current line-wires D. I have illustrated in scribe my invention as signal system employing alternating current for th e signal-circuits, since on roads operf lying one coil F of the. trank-relay-v for that 5 look. This relay is shownas of thephase induction type, the other n'ma'ry m1, ay-coil. G. 'bemg connected A and A represent portions of blocks in the- B represents the 'supplly-riplnductprsfor-tlie e t 'rd rai s or .tro

Fig. 1* and shall odeapplied to a blockpower-currentmay readily beprevented.

understood, how'everfthat in the opposite end of the block-A and sup-,

NEW Y RKQASSIGNOR TO I I ss v preceding block, but also by the signal for I the cross I anger? upon the train enclosedf t. e. ,1 a block is isolated only when the signal for that ly-operated road provided wit a blocki 2 to 4 show modifica-- In the drawi s, A, A, andA represent.

5 C C &'c.,'represent transformers sup ly' alternating signal-current to the and which are connected di-- rectly or through step-down transformers to;

'ated by direct current, which are at present I ;in the great majority, -it is desirable to use ialterna'ting current for the signal-circuits, as

p y directly or;

dicated t is type of relay, since it is one which is not affected by fluctuations of power-current in the primary of the transformer E which-supplies the .track-coilq The shortcircuited secondary member H is provided with a contact member which when both primary of l coils F and G are energized closes a circuit ating mechanismQJ operating mechanism is merely indicated through a source of current I and the operv of the signal Ka- The.

diagrammatically, and it will be understood that any welhknown type may be employed. 1 It will. be seen that the'central point of the transformer E is connected to the central point of the secondary of transformer C, supplying the adjacent block of the same, track. This connection is an ranged to afford a path forthe power-cue rent, so that the rails of the track may act as returnrconductor, and the particular connection shovm't.- e., between equipotential points of the alternating-current, signalcir cults is the same arrangement as is described,

' in Patents Nos. 645,907 and 641.7411, issued patents, this equi to 'Bedell-March 20, 19,00,-and April 17,.

1900, respectively.- As pointed out in those ables the same conductors to 'car'ry two cur-- rents of different kinds without mutual interference, since the direct current tends to divide equally betweenthe two portions of the transformer-wmdmg and has therefore no magnetizing efiect. V

' The arrangement as thus far described is one which has been proposed heretofore for 'been described in detail only for thepurpose use in electrically-operated roads and has of giving a clear-understanding of my present 1nvent1cn,'the specific arrangement and connections above described being in no way essential to'my invention in its broader aspects.

- It will be seen from the drawings that not adjacent blocks of the same track connected together, but cross connections only are are also made between the parallel tracks. With this cross connection it is evident that a break may occur in one of the rails ofa -block'as, for instance, atthe .point X in the block A--Without putting the signal for that I block at danger/Y since under these conditions current may flow. from the central ,G" in opposite directions, through the cross connection oint of the secondary of transformer C through the cross connection tothe opposite block, through the two portions of the primary of transformer E in opposite direction through the rails ofblock A through the two portions of the secondary of transformer to the ce'ntral'point of the primary of transformer E throu h the lower half of the primary winding, an through the lower rail back to the second lower terpotential connection en-- minal of transformer C", and this current in the primary of transformer E may be sufli cient to energize relay-coil F so as to hold signal K at clear.

In order to prevent an accident from this cause, I insert automatic switches in the several cross connections, as shown. Thus, for instance, a switch controlled by the magnet-coil M is arranged when 0 )encd to disconnect the entrance end of tie block A *from the opposite track, and consequently when this switch is c on a broken-rail in that blockis no longer shunted by the opposite track; but the signahcircuit is positively 'o ened and the signal must go to danger. h hr controlling this switch .I include the 'magnet'-,\vindir1 M 'across the line-wires D in series with three'sets of contacts, one set being 'the back contacts of the track-relay forthe block A another set hein g controlled by the signal K and closed when that signal is at. clear position, and a third set con trolled b an automatic switch in the opposite tracr one block ahead. Consequently when the signal K is at clear and a train enters the,block A short-circuiting the primary of transformer E and thereby dcencrgizing relaycoil F the movement ofthe sec onda member H to the relay will close the back contacts of the relay, thereby closing a circuit if the automatic switch of the other track is closed through the magnet M", which opens and holds open the switch which it controls,thcreby cutting ofi one end of the block A from the o posite track. Consequently if a rail is bro en in the block A. the signal K will indicate danger, and the train approaching in the block A will be properly warned.

Itwill be seen that. the switch is so arranged inthe cross connections that the op 'eration of the magnet )4 does not disturbthe connection between the block A and the 0 posite track. Furthermore, if the signal 12 is at danger the magnet M does not operate, and if the magnet operated, owing to the signal K being at clear, the switch controlled by the magnet is at once closed again when the front wheels of the train enter block A In other words, the cross'connew tions are closed at all times, thereby securing the maximum conductivity of the systei'n, except when"it is necessary that these con- 'nections should'be broken in order to protect against possible danger.

As has been said above, the circuit of the actuating-magnet for each automatic swil ch comprises contacts of the automatic switch for the opposite trackonc block ahead. The reason for thus interlocking the automatic switches is to prevent the return-circuit for the power-current formed by the track-rails from being broken entirely.

By reference to Fig. 1 it will be seen that if magnets h 2 and M were simultaneously energized the return-circuit for the powercurrent would be'completely broken. this reason the circuit of ma tended throughcontacts controlled by magnet Mfland the circuit of magnet includes contacts controlled by magnet M and .at the same time Consequently if either magnet is energized and its switch is opened the circuit of the other magnet is broken, so that; its switch cannot be'opened. opening of the power-circuit. is prevented,

protection against a broken rail is not interfered with, for it will be balanced pulsating seen that 'if magnet M en its switchand if there isa broken rail in book A at X thealternating signal-current of block 'A? can find no paththrough the arallel block A and consequently the signa K .will properly indicate danger. When re lays are employed of the type indicated in Fig. '1 or of any other type not affected by an unpower-current in the track-transformer, the automatic switches 'in Fig. 2. By this of switches required is halvedand the interwith. 3

' broken rail for if there is a broken rail in block tance' is ordinarily so Y the secondary of transformer C must need not necessarily I connections at the point shown in Fig. 1', but instead may be inserted at the points shown modification the number locking connections dispensed thev arrangement shown in Fig. 2 each automatic switch acts simpl to disconnect a block of'onetrack from the This arrangement with blocks of ordinary length gives suflicient protection againsta A at X, for, instance, the signal-current from total length of blocks'N', A, and-A I reach the other-"end of block -A". This dia greatthatthereno danger thatsuflicient signal-current will flow through the circuit as described above to I if a broken rai-l*"ex'ists. I the actu'ating magnets energize the relaykt-o close The connect ons of switches may b'ejunderstood from an Inspecsition and theitrack-relay' of the precedingnet M is connected to back contacts of rela tion ofthe drawings: I One terminal of magv the upper'line-wire D andfthe other terminal is connected to the lower line-wire D through two parallel circuits, one passing through switch LT and the armaturc H and thc otherpassing throng. switch L andjback contacts of the track-relay for block-At." I Thus niag'netQ M will be en ergizedrif-eithersignal K or- K (Not shown.)

isat clear poock'is energized. In other words, magnet I MFwill be. energized ifsignal K isfat clear and a train is. n block ""fclear and a "train in Consequently any block which a train is appreaching will be disconnected from'thc oppo- For. gnet M is eX-.

M similarly lenoid t I affected byt e power-current. In this way a completeis energized soas to be inserted inthe cross.

opposite track' without disconnecting it from the adjacent end of'the adjacent block of the same-track.-

1 for the automatics'witches, flo'w the in order to section "conductor connecting sides of the Insult ting-section. Between the the signal-circuit for the automaticblock A; or both.

It will be seen that if a train were in site track as long as the signal for that block is at clear position. The same principle may be applied to normal danger systems as well as to normal clear, and in such systems the application of this principle makes it possible tov employ track-relays of the usual soe, rendering it unnecessary to use track-re ays specially designed so as not to be one arrangement of automatic plied to-a normal tral point of the C', -,sup to bloc controlled b magnet M to both rails of block A". he track-relay N 2 is connected directly across the track-rails; the transformer shown in Figs. 1 and 2 between the" track-circuit and the track-relay'being omitted. The relay itself is shown as of-t'he simswitches apdanger system. The censecondary of transformer .Fig. 3shows plying the alternating signal-current A is connected through switches 8o ple solenoid tyge' Its winding is normally short-circuited net M signal K? is norin the block A, so block the signal K sulated sections and relays For instance, in block A I provide a short it which may be of; a single-rail length, 3r even less. This is bridged by a .theTails on opposite insulating-sectionand the opposite rail of the block is connected a relay 0 and a battery b so that whenever a train connects the insulated section a to the opposite rail the relay 0 is energized. When therelay O is energized, it closes a circuit from the lower linewireD, through the magnet M and through the contactspf the automatic switch at the entrance to. blockA. the automatic switch is energized when relay 0 disconnecting block A closed, magnet M is s energized, thereby from block A and Whenever magnet M he switch-contacts of magand consequently it normally maintains the circuit of the signal-actuating mechboth from block A and-.1

to respond to-a fiow 1 I (Notshown.) Provided from'the opposite track and j removing the short circuitfrom the relay N. This relay, in addition to closing the actuating-circuit of signal K closes a maintaining-circuit for magnet M so that the I magnet M remain open, the relay N ener gized, andthe signal train enters block A.

K at clear until the I I I switches controlled by Y A 'at the time that asecond train in block A? assed over the insulated rail-section a reinsert a second insulated rail-section a close to the exit end of the block A If signal K hasnot cleared, the-train comes to rest on the re insulated section a and waits there until 'the other train passes out of block A l As soon as this happens'relay N is energized, signal K is cleared, and the train in block A may proceed. The insulated section a r 5 rwould be placed at. a point in the track where 1 the train would naturally come to rest on find- .ing the signal K at danger, while the section a would be placed asufficient distance. back in the block so that the signal K woul clear in time to prevent the engineer fromseeing it at danger. andjapplying thebrakes. The actuating magnet for -,the automatic sv'vitches are interlocked in precisely. the same manner as described in Fig. 1, and it is believed that these connections require no fu ther explanation. r a

ployed for the return-conductor for the power current, v the connections may be somewhat simplified, as shown in Fig; 4. this figure 1 the batteries B. and B, &c., are indicated asthe's ource's of signal-current for the track- Icircuits, but any other sources maybe em-- v loyediif preferred. The switchicontrolled v magnet M connects, when closed, one rail these blocks are always insulated fromeach other. The track-relay N is connected 7 across the rails, of block A, and is shown as of i may be em loyed, since when. magnet MKis the'simple solenoid type. This type of relay energized t e block A is disconnected from the power-circuit, so that the'relayN rcannot be aiiected by the power-current; "The cir--' 5 cuit of magnet M? includes the switch L controlled by signal K and the back contacts of the track-relays for the block A..

It also includes a contact controlled by magnet M for the purpose of interlocking magnet M ,andM as has been heretofore explained. The artuating'magnets, as shown in this figure, are supplied with current directly from the power-circuit. The operation is precisely the same as has been hereto- .fore explained with reference to Fig. l. When a train is in block A,the track-relay for that block is deenergized, thereby closing its-back contacts,. so that if signal K is at clear and-magnet M note'iergized the magnet M? will open its switch, disconnecting ;-block A from the'other blocks, So that the the relay N will surely detect a broken rail or a train in'the block or anything else which would properly cause a danger indication of 6 the signal K r bi blocks A and A The other two rails'of I I have shown'the switch and magkpet onlydiag'rammatically, and in practice t ey may be of any suitable'construction. It is not at all necessary that the switch should be held closed by gravity and opened by the magnet, as shownin the drawings; but any'other desired arrangement may be 'used. Consequently I do not desire to limitmyself to the particulanconstruction and arrangement of parts here shown, but aim in the a pended claims to cover all modifications w ich' are within the scopeof my'inv'ention.

What I claim as new, and desire" to secure by Letters Patent of the United States, is-'- 1. In a block signal system for electrically- 8o operated roads having parallel tracks, 'con-.

nections between the track-circuits of adjacentparallel blocks adapted to afiord a return-path for thepower-current, and auto: matically-operated means controlling said. connections. I I Y 2;. Ina block-signalsystern for electricallyoperated-roads having paralleltracks; con nections between the track-circuits of .adja cent parallel blocks adapted to afford a re- 0.

. a turn-fath for the power current', switches in a :If only a single railgof each track is em 'serte in said connections, and automatic operating means for said switches- 3. In a block-signal system for electricallyoperatedroads having parallel tracks, con- 5 nections between! track-circuits of ad acent parallel blocks adapted to afford a'path for the power current, and means controlled by train movements for breaking said connections. 1

- Y mo 4-. Ina block-signal system for electricallyoperated roads 'havin parallel'tracks, connections between trac :circuits of ad acent. parallel blocks adapted to afford a -path "for the powercurrent,--switches inserte in said connections, and opprating means for saidswitches controlled y train movements.

5. In a block-signal system for electrically operated roads havin parallel tracks, a con'- nection from the trac circuit of a block to a no parallel track-circuit, said connection being adapted to afford a path for the power-current, a switch in said connection, and controlling means for said switch controlled by a train in the precedin block: I i u 5 6; In ablock-signa system for electricallyoperated roads having parallel tracks, a connection from the track-circuit of a block to a parallel track-circuit, said connection being adapted to afford a path for the powercurrent, a switch in said connection, and controlling means for said switchc'ontrolled by the signal apparatus of the preceding block.

7. In a block-signal system for electricallyoperated roads having parallel tracks, a con- 12'5 nection from the trac -circuit of a block to a parallel t1ltGl-Z-ClICl1lt, said connection being adapted to allord a path for the power-current, a switch in said connection, and controlling means for said switch controlled both 1 0 operated roads havin bylthesi the si na al apparatus of said block and by apparatus of the preceding block. a block-signal system for electricallyope'rated roads havin parallel tracks, a connection from-the 'trac -circuit of a block to a parallel track-circuit, said-connection being adapted to afford a path'for the power-current, a switch in said connectio 1, and means for automatically opening said switch when the signal for said block is at clear and a train is in the preceding block.

' 9. In a block-signal system for electricallyparallel tracks, a connection from the trac -circuit of a block to a parallel track-circuit, said connection being adapted to afford a path for'the power-current, a switch in said connection, and a magnet-winding controlling said switch.

10. In a block-signal system for electrically-operated roads having parallel tracks, a connection from the track-circuit of a block to a parallel track-circuit, said connection being adapted to afford a path for the powercurrent, a switch in net-winding controlling said means controlled by a train in the receding block controllin said magnetwin in 11." In a bloc -signal system for eIectricswitch, and

ally-operated roads having parallel tracks,-

a connection from the trackcircuit of a block to a parallel track-circuit, said connection being adapted to afford a path for the powercurrent, 'a switchin said connection, a magnet-winding controlling said switch, and a circuit for said magnet-winding comprising wswitch-contacts controlled bya train in the preceding block.

1-2. In a block-signal, system for electrically-operated roads havin parallel tracks, a connection from the trac -circuit of a block to a parallel track-circuit, said connection being adapted to afford a path for the powercurrent, a switch in said connection, a magnet-winding'controlling said switch, and a circuit for said magnet-windin comprising switch-contacts controlled by'tfie signal apparatus forsaid block and contacts controlled y-a train in the preceding block.

13. In a block-signal system for electrically-operated roads havingparallel tracks, connections between adjacent ends of the track-circuits of adjacent blocks in the same track and between both of said track-circuits and. the parallel track, and automatic the parallel track means for brea g the connection between one of the first-mentioned track-circuits and without disturbing the connection between the other of the firsti'nenlttioned. track-circuits and the parallel rac Y p 14; In' a bloekignal system .for electricto a said connection, a mag and operating means for "a connection from said ally-operated roads having parallel tracks, a conductor'connecting one end of the trackcircuit of a block to the adjacent end of the preceding block, a switch inserted in said conductor, and a connection from the other,

a switch inserted in said conductor, a connection from the other track point in said conductor between said switch and the preceding block, and means controlled by train movements, for opening said switch. I

16. In a block-signal system for electrically-operated roads having paralleltracks, means for su pl 'ng alternating current to the rails of a b 001?, an inductive winding con-. nected across the rails at one end of the block, a connection from said block to aparallel track adapted to forma path for the owercurrent, and automatic means contro led by train movements for breaking said connection.

17. In a block-signal system for electrically-operated roads having parallel tracks,

the rails of a bloc an inductive wlnding connected across the rails at one end of the block, a connection from said block to a parallel track, a switch inserted in said connection,

t'rollable by a train in the preceding block.

' ,18. In a block-signal system for electrically-operated roads having parallel tracks, means for supplying alternating current to the rails of a block an-inductive winding connected across the rails at one end of the blockblock to a parallel track, a switch in said connection, and means for automaticallyopening 'said switch when the signal for said block is at clearand a train is in. the preceding block.

19. In a block-signal system for electrically-operated roads having parallel tracks, means for suppl ing alternatingcurrent to the rails of a bloc an inductive winding connected across the rails at one end of the block, a connection from said block to a parallel track, a switch in said connection, and a magnet-winding controlling said switch.

said switch con- KOO IIO

In witness whereof I have hereunto set my I hand this 6th day of April, 1906.

. AURENCE A-. HAWKINS.

Witnesses:

BENJAMIN B. HULL, HELEN Onronn.

9 1 means for supplying alternating current to 

